An image projector is designed to present an image on a screen by projecting light onto the screen. To improve the quality of the image presented that way, image projectors and screens have been modified from numerous angles. Specifically, as for image projectors, the image display (modulation) methods and modulators have been modified so as to increase the efficiency. As for an image projection screen on the other hand, a high-reflection, high-contrast screen has been proposed.
For example, Patent Document No. 1 discloses an image projection screen including a polarization selective reflective layer with a cholesteric liquid crystal structure that selectively reflects light with particular polarization components.
Meanwhile, Patent Document No. 2 discloses a wavelength selective reflective image projection screen, which includes optical thin films with a high refractive index and optical thin films with a lower refractive index that have been alternately stacked one upon the other and which exhibits a high reflection property with respect to incoming light rays falling within particular wavelength ranges (associated with the three primary colors of R, G and B).
Furthermore, Patent Document No. 3 discloses an image projector including a laser light source that emits light rays in two of the three primary colors of light and an excitation light source laser that emits an excited light ray and also discloses a wavelength converting image projection screen that includes a phosphor for converting the wavelength of the excited light ray into that of the other color.
Furthermore, Patent Document No. 4 discloses a reflective image projection screen, on which provided is a light absorbing layer made of light absorbing ink that absorbs light in the vicinity of 575 nm (at which human eyes have the highest relative luminosity factor) such that the projected image does not lose a good gray balance.                Patent Document No. 1: Japanese Patent Application Laid-Open Publication No. 2005-292423        Patent Document No. 2: Japanese Patent Application Laid-Open Publication No. 2005-202029        Patent Document No. 3: Japanese Patent Application Laid-Open Publication No. 2003-287802        Patent Document No. 4: Japanese Patent Application Laid-Open Publication No. 6-82915        